pof3: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/share/doc/mh-book/examples/mh/bin/pof3 - from package: mh-book

You may install the required package with command apt-get install {package}

Error in other languages:
pof3: bevel nie gevind nie
pof3: comandă negăsită
pof3: comando não encontrado
pof3: commande introuvable
pof3: command not found
pof3: käsku ei ole
pof3: không tìm thấy lệnh
pof3: komanda nerasta
pof3: Kommando nicht gefunden.
pof3: kommandot finns inte
pof3: komut yok
pof3: nie znaleziono polecenia
pof3: níor aimsíodh an t-ordú
pof3: no se encontró la orden
pof3: no s'ha trobat l'ordre
pof3: opdracht niet gevonden
pof3: parancs nem található
pof3: perintah tidak ditemukan
pof3: príkaz nenájdený
pof3: příkaz nenalezen
pof3: команда не найдена
pof3: командата не е открита
pof3: 命令找不到
pof3: コマンドが見つかりません